SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bfb8b8236e7e55fcd10c6f0a9e6279e1d80608e3787da73dcb3c1f67f96ef96' 
  AND token = 'AYBx6rly7UJ6Qybe5Z6ZEIY+j/g/Be+TbgCANs57NMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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