SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '674872040bbd2539b29f40079e6a8e06f781ace955be55e04735af2b89b3df66' 
  AND token = '065JWxsnNjLY75zWdXCcyUXVPl5+tKLBz2h6K3Jwf5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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