SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '96677d19a115986b57cceecb5b36e7084e81e6782c6afbe654f2927c84a5d111' 
  AND token = 'DCH0ShWyceFPsuvLX8MRzm5qiGQbDw5nFgSrynZD8/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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