SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '338cfa9bf5b6a15d9be4822e77f4c42d30c47134618143ca998d5c347ddfb811' 
  AND token = '88S5o91AXXrs+CraqpJMO/q1y5xvBwKuNtmcsGgOSUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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