SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a61bdc54f9db098a0a247d910c7df18c33d4624373a45258875d05ae7bad6c8b' 
  AND token = '3BBDZpT/SYLr9uAGnAnXxeh4jrYlUq72oIJ9U+j6DyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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