SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb79afced7f0b92f56573962ef982758192271d0aba12dd33ed3f26178ef0968' 
  AND token = 'sWYZamR8EIstWPgoYZl1FGYbiMdxKigBt1p1gK89BCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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