SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9871192e9a49500c37ac691a3d0234fa15a3757865bb85dcfa8c3332a201efe6' 
  AND token = 'UhXzB4+z8SYVL8MxF4ii7KFjGDfgnCR61PZyJ+N3pMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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