SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ac261636e51808396d3a5b04cf6194e172122f640001d740f50808b2924dc18' 
  AND token = 'xvLv0hGJCKovsSBpzj07IcaNWRASZWTypyyXMoAsoi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00078

JSON explain

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