SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '566a8576231664a5e3663f17503b4607734951be999ccc114f2db5c18801df2c' 
  AND token = 'lzVuZz+ATxvR56dbSVnhaTpqq/KFxtgPCP1V4C7HsGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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