SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e0e11f3de94bc0ad973223ee1ec94f0b176bf7babe9d92f284143d2cf1aebc9' 
  AND token = 'KifNRUpcUnsDZBfCxWFBtW7CtdgZAy2v9/gwxbJjSWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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