SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20108ea7771041875335db77faa9f283d983db9b31d07cd8fcbe74e142f1b6b8' 
  AND token = 'YhixdjOJ9DEE9kytZyqBCQje8TJUKMi6I+EqdFReBbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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