SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0631e13fa7f8a53adfe724ffa6ff8a96daaf5e353fb6702dc51c9943e973d2b' 
  AND token = '4n0oDUYMaY+4OrAbb6s5ZDT1E7SBouNL0P7VHxBGC5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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