SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c3481036c0b2716a2b17924a7e480ac43185533a068895a8a5309384ee17b3e' 
  AND token = 'rbZCU4tEtCEpulM857S9dKxB9TJtdyjCmDbJTYu/YA4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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