SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b724eacadd61b6cc3d4655cadab85de7042d2b8713d80984dfc9af05f8f0aab2' 
  AND token = 'HDmz2jsjDIIllInehUToh4Hl+rw2/ZYbrNh5WCvF6sg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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