SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a557e5b6fbb9537686b8045d7a548199b6b4591f5fa16b8d10ab5bfd68e47f3d' 
  AND token = 'WgRgKBeVK5AaQ2PNVxOErCKHZjQgmxcvou/j7CD6ASs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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