SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f826b89324367b45f319e7144a7b521073c92c6a0d1627a74478b58663e41fda' 
  AND token = 'i9jwsYuNVHelx5cJU2uEDJpxeO3jrsCMf4HKD2T52RQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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