SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd299dd6f51c725dd619529bffd90ad288e23a01e0659832bbef4ccaf9a7d6537' 
  AND token = 'qj3TNVHpB6GiPqS/CKhWNQZwrEnKFIO7yjLnhYOAi00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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