SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8be1872b05464d8d781a72419897d0b4075764669099b747adffa990cb75854' 
  AND token = 'ceP7gAyeimx+jG10bK8bLHsP2WUVnGTBAoGDMXkJ/1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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