SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6e78a03d78fbbae6f1f4ce1d0da4f0a6111b4fa2105e12d3521bc0234ae8de54' 
  AND token = 'fxerVrY50jc5B6IJRMIsvK0Jagbq12Z6Hkuu5keB/6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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