SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a9d25b499db6486363cb5aa3e57abbc2f8cbab486dde6b2b653f78ef684f492' 
  AND token = 'FroAcYF1ycqFxVKDwJSfu/5oqTpvCJ9HQ1lkLd/aVuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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