SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6c44602f03ccf71ecece9831178477d1a5a90d866edefb4cca084ffd20eaeb1a' 
  AND token = 'vFSTsHTqOXbHhjhahgf1FifKcwT+NrxJRITX4AVljzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}