SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '804201466c83d0173b4191abad23d4d76ee6d2007c71e6bb52b836433e7daba0' 
  AND token = 'qExS0vmQciC3dnCOncjScFHrjp3TAE5mPtpANDHukRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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