SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f20285f7cc04e9480db3925417c2d2f6f33c8aeffc036462685a837529a094de' 
  AND token = '1mGOoTeNXwyUpA9AlbuOKmPqZDiAy/vG35+Tf9jmlkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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