SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '217b924f0bfdde5bd7187285f4fb66901c32a60e68a95189eeb4c2674734bfa7' 
  AND token = '1lsG1Xje55tTZhgwtrfr6AzBRje8uLzdgUgQwZMSgv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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