SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aca2273624b826d5e733ae44127c9f672ed0ad778a68cec0caabb7fd3a01fdb4' 
  AND token = '4hfFjz2smPc2d7IIoQxuyXTTtHIzOXxO9gDsEFCajpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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