SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1d74616144cd63abd50d4e1c6a3fcfe85c47c7f25333789cf30f8e97a4a5c3d' 
  AND token = 'g+o/ii5VAb1g+3ZLhgWkpNlQJjGgeXgKEMhrYqCRSD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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