SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0e39870feaa60078a5a8794f14355c0fe4995601799eb4510519daaf6120880d' 
  AND token = 'YpMPkEnkHcCV6v+W9FYssJpIWfRtBO3mXFfJofCYgqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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