SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf053fae3a3a8d9588b6a3cf0176bc88dcfb1dfa71ee59410783b210ea57597d' 
  AND token = 'a518MLRg20pTzd+aLQcsmmnPTb6qZVE05MJxt+MeMqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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