SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b64df155b7c7939eeacedbb91470de215bd422cd32756ba0e701477bab9d4c7e' 
  AND token = 'mMx5AxZPHGRCQYuvha2uzDZh8I8g1cyVFADwSrCYctU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00121

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}