SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fca914e578ab1f81ff136e661ea1eb8864d7f85e7d0b1c01f922cd85fbf6437' 
  AND token = 'GKYiUVZFpYaYWzjf0YBARwxO7Tstgoaea5xlG6dRaG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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