SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba15d83a6842e12d31b12e64ee7f234f5b3617fd30e1728bf7650d0e29842bb2' 
  AND token = 'oqQ2ZxFxQX8UxprI5BO3nNFIxCexmXGisjHtsVVfHbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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