SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba6e62ad76a2f32e37aa4f3e8d42124739e04ce540bfbebd118facf95023caea' 
  AND token = 'TBjFRu+C8/85pLIVWeDJ81czSzYfkFutKfi7MBC0UBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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