SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71827bbc0130a6a6ccc3ef0033a1639861c1b56985e03158e8557f0a0d12ce5d' 
  AND token = 'cCEuoCvz0cxyzSQdV8+dnNNdWCE2I+z/uCFAqWoBEbo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}