SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41760299c8c56314ecf4fd154ade4864185f0cffe0509e67bb1f0d49ed64fffe' 
  AND token = 'NFrkTuSwTQTpNxzbeARqd4rGvpZZQ9OR+cCu2pf+pKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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