SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8071c9eb49217327b5d1932bfeaa6dff870843aa5ae477a0c55d1532debe7348' 
  AND token = '+AtLxISonf8UaieLJ5BdgwtCD9jlNe3dBdI9ldkK7AM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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