SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac9da371e993b08d00f60ce0e30d1dda32b375318283e923d0eb026467a6bca7' 
  AND token = 'V6EivlwMk0s7/A3d/I9tfdLLv9vVQYr7CBy7YNhxJ+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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