SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '173f09081e516d137ea9625cd7c258f9ae0f803297279a5d523dc40e8df6437d' 
  AND token = 'iJQelunwRSFVWtZVDHGWsBV0Yhuk4q+2agA2shkScXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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