SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de7fd8387b88c2ae3b3990ca39f2708d42546428f46f1ebe3b7f3f93640219a0' 
  AND token = 'Fo2cespApi4qpbQYAPC9bXh4+F624Gh+aXgJS9Kn9Ik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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