SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc0c9c16af67fcdf7841a8e1b15dc1e5de1cab7e864c83dfdaca22eb313c8ae2' 
  AND token = 'tcUn/lBXJEPJ8Wjd754oQqirvXoRno/3+sFMxNtofrY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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