SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cbe7d15bd700ecff76ec2480ca42519d2bc5affeeb685f8a2feb67acf4d15ea' 
  AND token = 'm3WS6mVfiGQYsUXazl5jqWd1eNJsQEAmu7PteLH+dhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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