SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '569b8332c103d949860df07372a1894090d066ee687d2043ddb25ea6945d81e6' 
  AND token = 'bhj+PnS1Sx3nqI4xO8knPJuZtAulFwlgZ2vaQtyPgG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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