SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83bb61dd35d1fce731985d54d2c01a0daaba6d9280ee92750c9421d6d03bbe32' 
  AND token = 'AazafvZMWuVrJmOFOy2QnXOnGZlqriKU9thhjDVwDWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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