SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb43546ed2fe80a596d797855aa9c91a67dd03b2139e522060180566a84f54f9' 
  AND token = 'V4S+mseUTV/QYgBh6AJZNGr4JU1Bv7ro7aR/CPqJD5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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