SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'de2dcabd3e41cb95b3ebc8c0dda0eb955e5413f240d2667dbdcb6e9b3d190a46' 
  AND token = 'wNGajAgG/MK1f1LyJI7XT/vc8hMzI+jB7IoCgjxh1Ws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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