SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd262c558bd9622402b2a1c8c59d97b3e2e7aa9d309bbee0317413de717b4c2de' 
  AND token = 'z/K32RVkd8hvAK4RvuxJ56LACtcH8EcUJsj3680kvew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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