SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0368486657a9251999eebc23fbe696307ba80b7f028ab6bb547a1d39d663f45' 
  AND token = 'FDUYX+fY4+fxehFStREZS05o8C9qGg1OmZxggFEROmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}