SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c25d97febb911e0ff786967dca9c9bccccd233260dbed76e33fc432da287e387' 
  AND token = '8vDgrmCyjNjnagCorT/geYv1+YLUWhu7XLcyzTkBAw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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