SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5321fe5c6f74fdc6204b01cf1db50949b43a8f8cb91b5523d656d5572ea52465' 
  AND token = 'CxshN9KyYV+6/3PTX2jK/7NZHBTvysSdqM+ruQiT2Bw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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