SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '183381b48b163e6a921337954d295a6798287983a97da5b631965d14d5486efb' 
  AND token = 'NxQ7jmN/2sFrdt7yNtH4QVTaT9z9lXDnOiE/SyLQVCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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