SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd574dbc5b5c0bad19a5dff04d995323bd594d0dc6a688c60988fa1d40daf55c' 
  AND token = 'XHLhraAvAIXqHambwpsfkxL53Pl2Qj4g3f70lbQOIm0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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