SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f37101ae4d6832c85ed3f257e0b2a2c2b343d8598ec04f734848bc21998cc79' 
  AND token = 'tVbVNd5sbge6Wut4mIbijsxAkbGQ3rx5owO0QSkH+nk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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