SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ee937548424d22e6307f4a0265d76566fb10df0987b728b21bb9739ac982032' 
  AND token = 'd90JKNw7XQ36qQN3AYE8k3BIsjEEPnRmRDCaWZ0Zxnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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