SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7137c55c2fad540222b0fea88b9259cdaafd5d018566b2d2479da674c6a7ac68' 
  AND token = 'Mr0y2lWmEBfGdydbw2StuZY74hXv06MW8JMlzBHnlzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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