SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a48e7f1f5098504681b76748fe576e23b4b8a7de455e26ed769584b737964c20' 
  AND token = 'Meu5D5q2eJSR5H0o7Mto3NYUJS+lsDXgrWidtIvQz68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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