SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0948a9eaa20e2bdca7bf89894a1986ff22ae0d7006ec6155b30e68ceda5d031a' 
  AND token = 'K1f1wELuUsZKh05fHaNHcEyMUMrRQLFePTcVr2t2fXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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