SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be9fce2973306f9d0598a26219d589401fc7f33c391bfd972a426ebac88b70ee' 
  AND token = 'FFZ1mkezVL5ziEahcyIIGrlyCUirWyN5OIbAN5RHYsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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