SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1b49c879ade7e2929933f4d6eb091f98555b6c5b83298107e169abc89388a7b' 
  AND token = 'MTdHKMwTwI2WYMk8uvuykgJgBzDOllq9bn6bHwckPx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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