SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ad8427c5bb25d1afc5a25e322fdedad874e2544bba6b705ffd268ee3a2d415c' 
  AND token = 'QIkqvACGtDlAdEmkMMS1weuxfiRYzc3QIMqFHDHDDkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}