SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66140467c575657b9d7f0366ce4b0a9194194686708e984c1cb4438a96bfdd68' 
  AND token = 'Xo7uG1wJvYBJrhPRPj0RHCJYAkXwxNvd/0wS2JYD128=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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