SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0b14e577c569ea65c497c0e1bd94c62541e84f748e6e45addaeafc5fd31ae0d0' 
  AND token = 'mqSn+fvra92zPvImT9TZ4grd2vjWwzJkJpRuKDP5JdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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