SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e82a5648398caf2d932a17057b299f0d7c77e2529f517acfb3267fcbea4c7e6' 
  AND token = 'cwKSrpmU9G1oKuE8BifRvGTMP+43e2QLPHAArxMYjIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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