SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e0853c4e94044c9be4a1ac5e83623ec327593aff40754158f87063b5c165effb' 
  AND token = 'Fb9TSliDG/WkhYUoJXVTcAkmnhPG6tRgPWbbq/81UWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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