SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c5af800c23ad17589cfd80c90ee9aeb4d504bb50bffc1f80fbfd0883486431ca' 
  AND token = 'XsiRtRvbDPT0i49ikQGn8XEO03TfPEead8hLSrtFQXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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