SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce8ddce73e94ef039757e541efde259c50f5cf2b968c449ff40a54cbd4f85793' 
  AND token = 'rjbdCtiHaiZaS8aq7HxtrpMOwVltU0qiYtPeUkZV9zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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