SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75ea7055deeabf43ffd0508396a2cc138c08abaae3b00b0cb0790a4cd9e1c24e' 
  AND token = 'Xf23J6qicxgs2W41hjEEWyl2TiQ4BQfer3mEMLJqSvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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